Promoted low-temperature CO oxidation activity of CeO2 by Cu doping: The important role of oxygen vacancies

Abstract

Oxygen vacancies play key roles in improving the activities of catalysts. In this paper, the concentration of oxygen vacancies in a CeO2 catalyst was regulated by a series of Cu doping amounts to promote low-temperature CO catalytic oxidation. Characterizations and DFT calculations show that introduction of an appropriate amount of Cu generates oxygen vacancies and benefits their chemical stabilization, which activates the lattice oxygen and eventually improves the performance of the catalyst. The catalyst exhibits the best CO oxidation activity (T95 = 90.5 °C) when Cu/Ce = 0.2/0.8. This study establishes a theoretical foundation for enhancing CO oxidation by CeO2 at low temperatures by manipulating the oxygen vacancies.